Industrial robots are programmable machines that are designed for automatically handling or machining objects or, more specifically, workpieces. A typical representative is a so-called articulated robot that has a plurality of links, which are connected to each other by joints. In the simplest form such an industrial robot comprises a frame, on which a so-called carousel is arranged in a manner allowing rotation. A first arm of the robot, which is also referred to as a link arm, is fastened to the carousel by means of an additional pivot joint. An additional arm is disposed on this link arm by means of another pivot joint. This additional arm is provided on its free end with a receptacle for a tool. The tool is also referred to as an effector. Depending on the purpose of the industrial robot, a variety of tools may be provided, so that the industrial robot can have a multitude of applications, such as, for example, the handling and transport of objects and workpieces, the machining of workpieces, measurement tasks, etc. In order to handle objects or workpieces, a plurality of gripping tools for robots are already known from the prior art.
For example, the European Patent No. EP 1 943 064 B1 discloses a robot gripper, which is provided as an effector of a robot arm or may be attached to the end regions of linear or rotational drives. The prior art gripper comprises at least one frame and an actuator element that is mounted thereon and that has at least two gripper jaws or, more specifically, clamping jaws that can be actuated by means of an articulated unit. The actuator element is designed in the form of a bellows and can be filled with a medium, as a result of which said actuator element is capable of expanding and acts by means of a suitable force transmission element on the clamping jaws, in order to move them relative to each other, in order to be able to grasp objects. In this case the gripper itself has no safety devices that could prevent, for example, a person, who is working together with the corresponding robot, from being injured, in particular, crushed by the gripper. In the open state of the clamping jaws of the prior art gripper, it is namely possible for objects or also body parts of a person to be inadvertently inserted into the space between the two clamping jaws. If at this instant the actuator is actuated, then when the clamping jaws move, they may cause serious injury.